Mosquitofish Risky Business

A day of guest posts – this from Justa Heinen-Kay. Thanks Justa!

Imagine yourself walking down a street in a town known for its low crime rate. How would you behave? Would you explore new areas? Would you walk by yourself? Now imagine yourself walking down a similar street, but in a neighborhood known to have a high murder rate. Would you behave as you imagined in the safe neighborhood? Perhaps you would be less likely to explore an unknown street, and prefer to be with a group of others that you know? Many animals also experience environments that differ in riskiness, which could drastically impact how they behave. We tested this idea using the Bahamas mosquitofish that lives in inland blue holes across Andros Island, The Bahamas. These blue holes have fairly similar environments, except that a voracious predatory fish that specializes on mosquitofish inhabits some blue holes, but not others.

Using field and laboratory experiments, we found consistent and predictable behavioral differences between mosquitofish living in high predation risk vs low predation risk blue holes lacking predators (link to paper here). First, mosquitofish from predator-free populations were much more exploratory than their counterparts from risky environments. Mosquitofish from risky blue holes congregate in larger groups, showing more shoaling behavior. This is thought to be an anti-predator defense mechanism, because a predator is less likely to eat any one fish in a group than if by themselves. In predator-free blue holes, females were bolder and males were less aggressive (in general, male mosquitofish are much bolder than females). Differences in behavior can have cascading ecological and evolutionary consequences, so understanding how predictably animals behave in different ecological conditions is critical in a rapidly changing world.

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My lab’s interdisciplinary pursuits provide for a multi-faceted understanding of environmental change in the coastal realm. We are ecologists, asking questions that span population, community, ecosystem and evolutionary sub-disciplines. We often use a food web based perspective, exploring top-down (e.g., predation) and bottom-up (e.g., nutrient excretion) mechanisms by which animals affect ecosystem processes. All of our efforts are framed within a broader outreach framework, directly integrating science and education, using approaches such as this website.

One Comment

Dawn Wetzel
February 16, 2017 at 2:56 pm

Like the wolves in Yellowstone led to different behaviors of the herding, grazers.